Robot cleaner



FIG. 1 is a perspective view of a robot cleaner showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof where the right side view is a mirror image; and,

FIG. 5 is a top plan view thereof. 

The ornamental design for a robot cleaner, as shown and described. 